✨ allow sending multiple anchors when building line items

Author: ianardee

src/main/java/com/mindee/parsing/custom/lineitems/LineGenerator.java

@@ -6,6 +6,7 @@
 import com.mindee.parsing.custom.ListFieldValue;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.List;
 import java.util.HashMap;
 import java.util.Map;
 import org.apache.commons.math3.util.Precision;
@@ -19,25 +20,41 @@ public final class LineGenerator {
   private LineGenerator() {
   }
 
+  public static String findBestAnchor(
+      Map<String, ListField> fields,
+      List<String> anchors
+  ) {
+    String bestAnchor = null;
+    int anchorRows = 0;
+    for (String anchorName : anchors) {
+      ListField anchorField = fields.get(anchorName);
+      if (anchorField == null) {
+        throw new IllegalStateException("The field selected for the anchor was not found.");
+      }
+      if (anchorField.getValues().size() > anchorRows) {
+        anchorRows = anchorField.getValues().size();
+        bestAnchor = anchorName;
+      }
+    }
+    if (bestAnchor == null) {
+      throw new IllegalStateException("Could not determine which anchor to use.");
+    }
+    return bestAnchor;
+  }
+
   public static Collection<Line> prepareLines(
       Map<String, ListField> fields,
-      Anchor fieldAsAnchor
+      List<String> anchors,
+      double tolerance
   ) {
     HashMap<Integer, Line> table = new HashMap<>();
 
-    ListField anchor = fields.get(fieldAsAnchor.getName());
-
-    if (anchor == null) {
-      throw new IllegalStateException("The field selected for the anchor was not found.");
-    }
-
-    if (anchor.getValues().isEmpty()) {
-      throw new IllegalStateException("No lines have been detected.");
-    }
+    String anchorName = findBestAnchor(fields, anchors);
+    ListField anchor = fields.get(anchorName);
 
     // handle one value and the case of one line
     int lineNumber = 1;
-    Line currentLine = new Line(lineNumber, fieldAsAnchor.getTolerance());
+    Line currentLine = new Line(lineNumber, tolerance);
     ListFieldValue currentValue = anchor.getValues().get(0);
     currentLine.setBbox(currentValue.getPolygon().getAsBbox());
 
@@ -50,7 +67,7 @@ public static Collection<Line> prepareLines(
           Precision.equals(
             currentLine.getBbox().getMinY(),
             currentFieldBbox.getMinY(),
-            fieldAsAnchor.getTolerance()
+            tolerance
           )
       ) {
         currentLine.setBbox(
@@ -60,7 +77,7 @@ public static Collection<Line> prepareLines(
         // when it is a new line
         table.put(lineNumber, currentLine);
         lineNumber++;
-        currentLine = new Line(lineNumber, fieldAsAnchor.getTolerance());
+        currentLine = new Line(lineNumber, tolerance);
         currentLine.setBbox(currentFieldBbox);
       }
     }

src/main/java/com/mindee/parsing/custom/lineitems/LineItemsGenerator.java

@@ -1,9 +1,9 @@
 package com.mindee.parsing.custom.lineitems;
 
 import com.mindee.geometry.MinMax;
-import com.mindee.geometry.PolygonUtils;
 import com.mindee.parsing.custom.ListField;
 import com.mindee.parsing.custom.ListFieldValue;
+import java.util.Collections;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -19,8 +19,39 @@ private LineItemsGenerator() {
   }
 
   /**
-   * WARNING: This feature is experimental!
-   * Results may not always work as intended.
+   * Generate line items.
+   * Use this method if you want to send a list of different possible anchor fields.
+   * All anchor fields will use the same tolerance.
+   */
+  public static LineItems generate(
+    List<String> fieldNames,
+    Map<String, ListField> fields,
+    List<String> anchors,
+    double tolerance
+  ) {
+    Map<String, ListField> fieldsToTransformIntoLines = fields.entrySet()
+      .stream()
+      .filter(field -> fieldNames.contains(field.getKey()))
+      .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
+    return generate(fieldsToTransformIntoLines, anchors, tolerance);
+  }
+
+  /**
+   * Generate line items.
+   * Use this method if you want to send a list of different possible anchor fields.
+   * Use the default tolerance for all anchors.
+   */
+  public static LineItems generate(
+    List<String> fieldNames,
+    Map<String, ListField> fields,
+    List<String> anchors
+  ) {
+    return generate(fieldNames, fields, anchors, 0.01d);
+  }
+
+  /**
+   * Generate line items.
+   * Use this method if you want to use a single anchor field.
    */
   public static LineItems generate(
       List<String> fieldNames,
@@ -31,13 +62,27 @@ public static LineItems generate(
         .stream()
         .filter(field -> fieldNames.contains(field.getKey()))
         .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
+    List<String> anchors = new ArrayList<>(
+        Collections.singletonList(anchor.getName())
+    );
+    return generate(fieldsToTransformIntoLines, anchors, anchor.getTolerance());
+  }
 
+  private static LineItems generate(
+      Map<String, ListField> fieldsToTransformIntoLines,
+      List<String> anchors,
+      double tolerance
+  ) {
+    List<Line> preparedLines = new ArrayList<>(LineGenerator.prepareLines(
+        fieldsToTransformIntoLines,
+        anchors,
+        tolerance
+    ));
     List<Line> lines = populateLines(
         fieldsToTransformIntoLines,
-        new ArrayList<>(LineGenerator.prepareLines(fieldsToTransformIntoLines, anchor)),
-        anchor.getTolerance()
+        preparedLines,
+        tolerance
     );
-
     return new LineItems(lines);
   }
 

src/test/java/com/mindee/parsing/custom/lineitems/LineGeneratorTest.java

@@ -1,62 +1,67 @@
 package com.mindee.parsing.custom.lineitems;
 
+import java.util.ArrayList;
 import java.util.Collection;
-
+import java.util.Collections;
+import java.util.List;
 import org.apache.commons.math3.util.Precision;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
 class LineGeneratorTest {
 
+  private static final List<String> anchors = new ArrayList<>(
+      Collections.singletonList("names")
+  );
+  private static final double tolerance = 0.01d;
+
   @Test
   void prepareLinesWith2ValuesOnEachLineWithPolygonValuesOnExactlyTheSameAxis() {
-    Anchor anchor = new Anchor("names");
-
     Collection<Line> table = LineGenerator.prepareLines(
       FakeListField.getWith2ValuesByExpectedLines(),
-      anchor
+      anchors,
+      tolerance
     );
-
     Assertions.assertEquals(2, table.size());
   }
 
   @Test
   void prepareLinesWith1FieldValueForTheLastLine() {
-    Anchor anchor = new Anchor("names");
-
     Collection<Line> table = LineGenerator.prepareLines(
-        FakeListField.getWith1FieldValueForTheLastLine(), anchor);
-
+        FakeListField.getWith1FieldValueForTheLastLine(),
+        anchors,
+        tolerance
+    );
     Assertions.assertEquals(3, table.size());
   }
 
   @Test
   void prepareLinesWith1ExpectedLine() {
-    Anchor anchor = new Anchor("names");
-
     Collection<Line> table = LineGenerator.prepareLines(
-        FakeListField.getWith1ExpectedLines(), anchor);
-
+        FakeListField.getWith1ExpectedLines(),
+        anchors,
+        tolerance
+    );
     Assertions.assertEquals(1, table.size());
   }
 
   @Test
   void prepareLinesWithPolygonsNotExactlyOnTheSameAxis() {
-    Anchor anchor = new Anchor("names", 0.005d);
-
     Collection<Line> table = LineGenerator.prepareLines(
-        FakeListField.getWithPolygonsNotExactlyOnTheSameAxis(), anchor);
-
+        FakeListField.getWithPolygonsNotExactlyOnTheSameAxis(),
+        anchors,
+        0.005d
+    );
     Assertions.assertEquals(2, table.size());
   }
 
   @Test
   void prepareLinesWhichRender2LinesInsteadOfOne() {
-    Anchor anchor = new Anchor("names", 0.0d);
-
     Collection<Line> table = LineGenerator.prepareLines(
-        FakeListField.getSampleWichRender2LinesInsteadOfOne(), anchor);
-
+        FakeListField.getSampleWichRender2LinesInsteadOfOne(),
+        anchors,
+        0.0d
+    );
     Assertions.assertEquals(1, table.size());
   }